Grandson drowned phone.

My 2 year old grandson has been using this Motorola XT1527 on wifi to watch educational videos on youtube, making him pretty smart too...lol.
A couple of days ago he dunked it in the toilet...lol
I dried it out in a bag of rice on a warm radiator for a few days, couldn't get the battery out since it's built in.
It does nothing until power is applied via the USB port. Then the Motorola/Android splash screen comes on and goes off over and over.

I can press power and volume down and this comes up:
At first the screen displayed Battery Low in red, Now, when first put in to the menu screen, it show Battery OK (Charging), then after a minute shows Battery OK.
If I try to get to recovery mode, or any other selection, it goes back to looping the splash screen. The only selection on the menu that works is Bar Codes, they come up.
Do you think there is a chance to somehow make the phone work again or is it toast?